Photographic multicolor diffusion transfer process using dye developers and element



Nov. 3, 1970 R. w. BECKER 3,537,349

' PHOTOGRAPHIC MULTICOLOR DIFFUSION TRANSFER PROCESS USING DYEDEVELOPERS AND ELEMENT 4 Filed 001;. 22, 1968 SUPPOR T RECEPTION LAYERALKALINE QUATERNARY AMMONIUM SALT PROCESSING coMPosmoN HYDROQUINO NEDERIVATIVE LAYER 1 BLUE SENSITIVE EMULSION LAYER YELLOW DEVELOPER LAYERSfagel INTERLAYER GREEN-SENSITIVE EMULSION LAYER m MAGENTA DYE DEVELOPERLAYER INTERLAYER 1 RErJ-sENsmvE EMULSION LAYER n DYE DEVELOPER LAYER mSUPPORT YELLOW IMAGE l 21 MAGENTA IMAGE 28 CYAN IMAGE S lage 2 I :2: wRichardWBec/cer IN V EN TOR.

IURNEYJAGBNT United States PatentOffice Patented Nov. 3, 1970 3,537,849PHOTOGRAPHIC MULTICOLOR DIFFUSION TRANSFER PROCESS USING DYE DEVEL-OPERS AND ELEMENT Richard W. Becker, Rochester, N.Y., assignor toEastman Kodak Company, Rochester, N.Y., a corporation of New JerseyContinuation-impart of application Ser. No. 368,490, May 9, 1964, whichis a continuation-in-part of application Ser. No. 71,314, Nov. 23, 1960.This application Oct. 22, 1968, Ser. No. 776,849 The portion of the termof the patent subsequent to May 31, 1983, has been disclaimed Int. Cl.G03c 7/00 US. Cl. 96-3 9 Claims ABSTRACT OF THE DISCLOSURE Photographicelements are described comprising a support having coated thereon red,green and blue imageforming units comprising, respectively, a redsensitive emulsion layer having an underlying, contiguous cyan dyedeveloper layer; a green sensitive emulsion layer having an underlyingcontiguous magenta dye developer layer; and, a blue sensitive silverhalide emulsion layer having an underlying contiguous yellow dyedeveloper layer. The light-sensitive elements utilize gelatininterlayers on either side of the dye forming unit therein which recordsthe green light. Substantially colorless hydroquinones which areinsoluble and dilfusible in alkaline liquids, as well as onium compoundsthat are difl'usible in alkaline liquids, are useful in the describeddye developer system.

This application is a continuation-in-part application of Ser. No.368,490, filed May 19, 1964, which issued as US. Pat 3,411,904, andwhich in turn was a continuationin-part of Ser. No. 71,314, filed Nov.23, 1960, now abandoned.

The present invention relates to the art of photography, and moreparticularly, to dye diffusion transfer systems utilizing dyedevelopers.

Compounds which contain in the same molecule both the chromophoricsystem of a dye and a photographic silver halide developing moiety havebeen described in the photographic art as useful compounds inphotographic elements for preparing color images by diffusion transferprocesses. Such compounds are commonly called dye developers.Photographic elements containing such dye developers generally comprisea plurality of photosensitive silver halide emulsions wherein each ofthe emulsions is selectively sensitized to a different region of thespectrum. A dye developer is positioned contiguous to the silver halidein each of such emulsions. Such a photoelement is processed with analkaline composition and the latent image is developed in the negativeimage areas with the dye developers, this development immobilizing thedye developers in such negative image areas, and the dye developers inthe unexposed areas diffuse to the surface imagewise and are transferredto a reception layer or receiving sheet to form a positive multicolorimage. Such color difiusion transfer processes are disclosed in US. Pat.No. 2,983,606 and British Pat. 804,971, as well as elsewhere in theliterature.

Many problems are encountered in multicolor dye developer diffusiontransfer systems that are different than corresponding monochromesystems and other multicolor systems. For example, in multicolor dyedeveloper sys tems, the development products of one emulsion tend toaffect the development of the other emulsions, the diffusion of a dyedeveloper from a lower layer can be affected, i.e., be hindered, by adye developer or other substance in an upper layer, the exhaustion ofthe processing solution by an outer layer may affect development of alower layer and one layer may not develop to the extent of anotherlayer, and particularly, one dye developer may not be immobilizedsufficiently to prevent it from transferring and causing colorcontamination of a dye image of another color. Also, a given dyedeveloper may develop some grains of silver halide in the wrong emulsionlayer with the result that an insuflicient amount of that dye developeris available for transfer and the corresponding colors are unsaturated.Thus a magenta dye developer may develop some grains of red-sensitivesilver halide and become immobilized, this decreasing the magentaavailable to produce red colors which then appear unsaturated.Concomitantly, because of the undesired development of the red-sensitiveemulsion layer by the magenta dye developer, some of the cyan dyedeveloper which should have developed the red-sensitive emulsion layeris free to diffuse, this resulting in an even greater desaturation ofthe red colors. Degradation of color quality due to dye developerdeveloping silver halide in the wrong emulsion layer is referred to ascolor drop off.

It is an object of this invention to provide a novel multicolordiffusion transfer process utilizing dye developers.

It is another object of this invention to provide a novel photographicprocess that is useful in preparing multicolor dye developer imageshaving reduced color contamination.

It is another object of this invention to provide a novel dye diffusiontransfer process for preparing multicolor dye developer images havingreduced color drop-off.

It is still another object of this invention to provide a newphotographic element suitable for preparing multi: color dye developerimages.

These and other objects of the invention are accomplished withlight-sensitive photographic elements comprising a support having coatedthereon three superposed dye image-forming units capable of recordingred, green and blue light, each of such units comprising agelatinosilver halide emulsion layer and an underlying contiguous layercontaining a dye developer in a gelatin substrate substantiallycomplementary in color to the color of light recorded in the contiguoussilver halide emulsion. The dye image-forming unit that records bluelight is farthest from the support and contains a yellow dye developer,the dye image-forming unit that records red light is most proximate tothe support and contains a cyan dye developer, and the dye image-formingunit that records green light and contains a magenta dye developer ispositioned between the other units. In accordance with the invention,gelatin interlayers of a specified thickness are utilized on either sideof the dye image-forming unit recording green light to separate it fromthe other dye image-forming units. The gelatin interlayers of theinvention should be about to 3 times as thick as and containing about 2to 6 times as much gelatin as the dye developer layer containing theyellow dye developer. The layer containing the yellow dye developertypically is about .01 to .1 mil in thickness and contains about 25 to250 mg. of gelatin per square foot. The interlayers function to delaydiffusion of dye developer from one dye image-forming unit to anotherdye image-forming unit for a time sufficient to effect substantialdevelopment of the respective silver halide emulsions by dye developerfrom the said layer coated contiguous to each such emulsions when saidelement is processed in the presence of an alkaline liquid.

Another important feature of the photographic elements of the inventionis the use of a substantially colorless and substantiallyWater-insoluble hydroquinone soluble and ditfusible in alkaline solutionthrough the gelatin layers of the elements positioned in at least one ofthe layers on the emulsion side of the elements. Such hydroquinonecompounds, in cooperation with the gelatin interlayers described above,produce results not attributable to either of these features separately.Also, the subject photographic elements are preferably processed oractivated with alkaline processing compositions containing an oniumcompound that is soluble and diifusible in alkaline solution through thegelatin layers of the elements.

The dye developer diffusion transfer system of the invention producespositive color image transfer prints that are particularly characterizedas having improved color density and color purity.

Dye developers are well known in the photographic art. Such compoundsfunction both as a silver halide developing agent and as a dye inphotographic diffusion transfer systems. Dye developers arecharacterized as being relatively nondiffusible in colloid layers suchas the hydrophilic organic colloids used in photographic emulsions atneutral pH, but diffusible in the photographic elements in the presenceof alkaline processing solutions. Generally, such dye developers aresubstantially insoluble in water, which property usually necessitatesthe use of organic solvents to incorporate the dye developers into theorganic colloid layers of the photoelements. The dye developers areparticularly characterized as containing both a chromophoric or dyemoiety and at least one moiety having a silver halide developing agentfunction. Particularly useful dye developers are those wherein thechromophoric moiety is an azo or anthraquinone dye moiety and the silverhalide developing moiety is a benze noid moiety such as a hydroquinonylmoiety.

Representative dye developers of use in the dispersions of the inventionhave the general formula MN=ND in which M is an aromatic or heterocyclicring or ring system such as a benzene, naphthalene, tetralin,anthracene, anthraquinone, pyrazole, quinoline, etc., ring which can besubstituted with such groups as hydroxyl, amino, keto, nitro, alpoxy,aryloxy, acyl, alkylamido, arylamido, alkylaryl, carboxamido,sulfonamido, carboxyl or sulfo groups. D represents a silver halidedeveloping agent moiety imparting the developing agent function to thedye developer such as a hydroquinonyl group which can be substitutedwith amino, alkylamino, alkyl, hydroxyl, alkoxyl or halogen groups.

A useful class of dye developers is disclosed in Australian Pat. 220,276and German Pat. 1,036,640, typical members of the class being listedbelow.

4- [p- 2,5'-dihydroxyphenyl phenylazo] -5-acetamidol-naphthol 4- [p 2',5-dihydroxyphenethyl) -phenylazo] -5- benzamido- 1 -naphthol1-phenyl-3-methyl-4- [p- 2',5 -dihydroxyphenethyl phenylazo-5-pyrazolone 2- p- 2,5'-dihydroxyphenethyl -phenylazo] -4- acetamido- 1-naphthol 2- p- 2',5 '-dihydroxyphenethyl phenylazo] -4- aminol-naphthol2- [p- 2',5-dihydroxyphenethyl) -phenylazo -4- methoxy- 1 -naphthol 2-p- 2',5 -dihydroxyphenethyl) -phenylazo -4- ethoxyl-naphthol 2- [p- 2',5'-dihydroxyphenethyl) -phenylazo -4-npropoxy- 1 -naphthol1-phenyl-3-N-n-butyl-carboxamido-4-[p-(2',5-

dihydroxyphenethyl) -phenylazo] -5-pyrazolone1-phenyl-3-N-n-hexylcarboxamido-4- [p-(2,5-

dihydroxyphenethyl) -phenylazo] -5-pyrazolone1-phenyl-3-carbethoxy-4-[p-( 2',5 -dihydroxyphenethyl)-phenylazo]-5-pyrazolone 2- [p- 2',5 -dihydroxyphenethyl) -phenylazo -4- iso propoxyl -naphlhol 1-phenyl-3-N-cyclohexylcarboxamido-4- [p-(2',5'-dihydroxyphenethyl)phenylazo]-5-pyrazolone 1-phenyl-3-phenyl-4- [p- 2',5-dihydroxyphenethyl) phenylazo]-5-pyrazolone 2-(4- [p-(2",5"-dihydroxyphenethyl)-phenylazo] a-naphthylazo-4-methoxy-l-naphthol1-phenyl-3-amino-4-(4-[p-(2",5"-dihydroxyphenethyl) -phenylazo]-2,5-diethoxyphenylazo -5- pyrazolone l-acetoxy-Z- [p-(fl-hydroquinonylethyl) -phenylazo 1 4-methoxy naphthalene4-isobutoxy-2- p- (p-hydro quinonylethyl) -phenylazo l-naphtholl-acetoxy-Z- [pfl-hydroquinonylethyl) -phenylazo 4-propoxy naphthalene2- p- 2',5 -dihydroxy-4-methylphenethyl -phenylazo 4-propoxy-l-naphtholl-phenyl-3-(N-n-heptyl)-carboxamido-4-[p-(flhydroquinonylethyl-phenylazo] -5-pyrazolonel-(o-carboxyphenyl)-3-phenyl-4-[p-(2,5-trifiuoro acetoxy-p-phenylethyl)-phenylazo] -5-hydroxy pyrazole lactone 1- (o-carboxyphenyl)-3-N-phenylcarboxamido-4- [p- B'-hyd roquinonylethyl) -phenylazo] -5-hydroxypyrazole lactone Another useful class of dye developers isdisclosed by British Patent 804,971 and British Patent 804,973, severalbeing listed below. 1,4-bis (2',5'-dihydroxyanilino) -anthraquinone1,5-bis(2',5'-dihydroxyanilino)-4,8-dihydroxyanthraquinone 1,4-bis[fl-(3',4-dihydroxyphenyl) -ethylamino] anthraquinone1,4-bis[fl-(2,5'-dihydroxyphenyl)-isopropylamino]- anthraquinone1,4-bis[fl-(2,5-dihydroxyphenyl)-ethylamino]- anthraquinonel-chloro-4-[fl-(2',5'-dihydroxyphenyl)-ethylamino]- anthraquinone'N-monobenzoyl- 1,4-bis [/3-( 3 ,4-dihydroxyphenyl)ethylaminoJ-anthraquinone N-monobenzoyl-1,4-bis [[3- (2',5'-dihydroxypheny1) ethylamino]-anthraquinone 5,8-dihydroxy-1,4-bis[B-hydroquinonyl-u-methyl)- ethylamino]-anthraquinone (Compound I)1,4-bis (B-hydroquinonyl-a-ethyl) -ethylamino] anthraquinone5-hydroxy-1,4-bis (fl-hydroquinonyl-a-methyl) ethylamino]-anthraquinone1-(ii-hydroxy-tx-ethyl-ethylamino)-4-(/8-hydroquinonyla-methyl-ethylamino-anthraquinone1-(butanol-2'-amino)-5,8-dihydroxy-4-hydroquinonylisopropylamino-anthraquinoneAlso useful are the following dye developers. Cyanurated dye developerssuch as 2-hydroquinonearnino-4-(pphenylazo)-anilino-6-hydroXy-4-triazinedescribed in Canadian Pat. 579,038. Anthraquinone dye developers such as1,4-bis(2, -dihydroxyaniline)-anthraquinone and 1,4- diamino-N-(B-2',5dihydroxyphenyl oz methyl-ethyl)- 2,3 anthraquinone dicarboximide.Amino-substituted anthraquinone dye developers such as prepared byreaction of 1 amino 4 (p aminoanilino) anthraquinone- 2-sodium sulfonatewith chloroacetamido hydroquinone monobenzoate. Dye developers obtainedby reaction of 1-phenyl-3-amino-4-phenylazo-5-pyrazolone or 1,4-bis( 8-aminoethylamino)-anthraquinone with homogentistic acid lactone or acidchloride, or gentisic acid chloride, e.g., 1 phenyl 3 (2',5'dihydroxyphenylacetamido) 4 phenylazo 5 pyrazolone described in CanadianPat. 577,021. Naphthamide dye developer such as 1-(2,5-dimethoxyphenylazo) 2 hydroxy N (2',5' dihydroxyphenyl)-3-naphthamidedescribed in French Pat. 1,168,292. Diazo dye developers such asZ-[p-(I-hydroxy- 3,6 disulfo 8 amino 2 naphthylazo) 3,3dimethoxybisphenyleneazo]hydroquinone and 2-(2',5-dimethoxy 4 [p (2",5dihydroxyphenethyl) phenylazo1- phenylazo)-1,S-naphthalenediol-3,6-disu1fonic acid. Arylazonaphthol dye developers, e.g.,1-amino-4-phenylazo-2- naphthol. Anthrapyridone dye developers, e.g.,l-acetyl-3- B (2,5 dihydroxyphenyl) ethyl 6 ,9 (2,5' dihydroxyphenyl)ethylarnino anthrapyridone. Thiohydroquinolyl dye developers, e.g.,1-phenyl-3-methyl-4-[p- 2', 5 dihydroxyphenylthioethyl) phenylazo] 5pyrazolone described in Belgian Pat. 568,344. Orthocoupled dyedevelopers exhibiting limited sensitivity to changes of pH, e.g., 2 [p(2",5" dihydroxyphenoxy) phenylazo] 4-methoxy-l-naphthol and1-phenyl-3-methyl-4-[phydroquinolylsulfonyl)-phenylazo]-5-pyrazolone.Oxalyl ester dye developers, e.g., 1-phenyl-3-amino-4-[p (2,5 bisethoxalyloxyphenethyl) phenylazo]-5-pyrazolone. Leuco compounds can alsobe used similarly, e.g., 1-phenyl-3- methyl 4 (2 methyl 4 diethylamino)anilino 5 pyrazolone, which do not exert a filtering action onunderlying emulsion layers and which are'immobilized in the developedregions, diffuse imagewise from undeveloped acres to the reception layerand are oxidized to colored images therein. Additional suitable dyedevelopers are disclosed in Belgian Pat. 554,935, British Pats. 84,971,804,974-5 and French Pat. 1,168,292.

In the photographic elements useful in the invention, the dye developersare preferably incorporated in gelatin vehicles or carriers comprisingthe layers of the photographic element dissolved in high'boiling orcrystalloidal solvents and dispersed in finely-divided droplets. Inpreparing such dispersions of dye developers, high-boiling orsubstantially water-immiscible organic liquids having boiling pointsabove about 175 C. are utilized. The high boiling solvent can "be usedalone in dissolving the dye developer and in forming the dispersion orit can be mixed with a low-boiling organic solvent (e.g., boiling atleast C. below the boiling point of the higher -boiling solvent), or aWater-soluble organic solvent, as an auxiliary solvent to facilitatesolution of the dye developer. A preferred range of proportions ofhigh-boiling solvent to auxiliary is 1/0 to 1/ 10 on a weight basis.Such auxiliary solvents can be readily removed from the colloidalvehicle by air-drying a chilled, noodled dispersion or by continuouswater washing. Typical high-boiling, water-insoluble solvents that canbe used to dissolve dye developers in preparing the dispersions of theinvention are described on page 2, col. 2 and page 3, col. 1 of US. Pat.No. 2,322,027.

The dye developers utilized in the photographic ele ments useful in theinvention can also be incorporated into vehicles soluble in organicsolvents which are also solvents for the dye developers. Likewise, otherincorporating techniques for the dye developers such as ballmilling canbe utilized.

Each of the dye developers is positioned in a gelatin sublayercontiguous to the respective silver halide emulsion layers. A silverhalide emulsion layer and its contiguous dye developer-containing layercomprises a dye image-forming unit of the invention. The dye developersare substantially complemetnary in color to the color of the lightrecorded or spectral sensitivity of the silver halide emulsionscontiguous thereto.

A wide variety of colorless hydroquinone derivatives can be utilized inthe dye developer diffusion transfer systems of the invention. Suchcolorless hydroquinone derivatives are substantially insoluble in waterand diffusible in the hydrophilic organic colloids comprising thepresent photographic elements in the presence of alkaline processingcompositions. Typical suitable colorless hydroquinone derivatives arelisted below.

phenylhydroquinone 2-hydroxyphenylhydroquinone phenoxyhydroquinone4'-methylphenylhydroquinone 6 1,4-dihydroxynaphthalene2-(4-aminophenethyl)-5-bromohydroquinone 2- (4-aminophenethyl-5-methylhydroquinone 4'-aminophenethylhydroquinone2,S-dimethoxyhydroquinone 2,5-dibutoxyhydroquinone m-xylohydroquinonebromohydroquinone 3 ,6-dichlorohydroquinone2-dimethylaminomethyltoluhydroquinone 2-cyclohexylhydroquinonesec.-butylhydroquinone 2,5-dichlorohydroquinonc2,5-diisopropylhydroquinone 2,5-diiodohydroquinone3-chlorotoluhydroquinone tetrachlorohydroquinone2,5-diphenylhydroquinone 2,5-diresorcylhydroquinone2,5-dioctylhydroquinone dodecylhydroquinone In the present dye developerdiffusion transfer systems, the hydroquinone derivative can be presentin any of the layers of the light-sensitive or negative element such asin an overcoating layer, in a silver halide emulsion layer, in a dyedeveloper layer, or in an interlayer. The hydroquinone derivatives arepreferably used in one or more layers of the light-sensitive element inquantities of the order of about 10 to 10 mg. of more per square foot.However, the quantity used can be widely varied and depends in part onthe amount of silver halide in the emulsion layers.

A wide variety of diifusible onium compounds can also be utilized in thepresent invention. Such onium compounds, that is, compounds that containan organic cation, are diffusible in the hydrophilic organic colloidscomprising the present photographic elements in the presence of alkalineprocessing compositions. Such onium compounds are typically quaternaryammonium compounds, quaternary phosphonium compounds or tertiarysulfonium compounds. The onium compounds can be used as hydroxides or asother types of salts. Typical suitable quaternary ammonium compoundshave the formulas typical suitable quarternary phosphonium compoundshave and typical suitable tertiary sulfonium compounds have the formulaIn the above formulas: R to R are each organic radicals such as alkylradicals, aryl radicals, aralkyl radicals of the benzene series, andincluding substituted alkyl, aryl or aralkyl radicals, the alkyl chainsgenerally being 1 to 18, and preferably 1 to 4, carbon atoms, and thearyl radicals preferably being phenyl; X is an anion including hydroxylor an anion derived from an acid such as bromide, chloride, p-toluenesulfonate, perchlorate or the like; and Z and Z each represent thenonmetallic atoms necessary to complete a heterocyclic ring generallyhaving 5 to 10, and preferably 5 or 6 atoms in the heterocyclic nucleussuch as carbon, nitrogen, oxygen, selenium and sulfur atoms to form suchheterocyclic rings as pyridine, quinoline, benzoquinoline, benzoxazole,benzoselenazole, thiazole, benzothiazole, piperidine, naphthothiazole,benzimidazole,

Z3 R a 1 R"N (=CIICII) Fri-( 111 X- 1115 wherein: X is an anion asdescribed above, It is an integer 15 of 0 or 1. Z represents thenonmetallic atoms necessary to complete a heterocyclic ring as describedabove for Z and Z but is preferably a pyridine ring, R and R are eitherhydrogen atoms or lower alkyl radicals having 1 to 4 carbon atoms, and Ris an organic radical as described above for R to R Typical oniumcompounds that can be utilized in the present invention are listedbelow.

l-benzyl-Z-picolinium bromide 2r-1-(3-bromopropyl)-2-picolinium-p-toluenesulfonatel-phenethyl-Z-picolinium bromide 1-'y-phenylpropyl-2-picolinium bromide2,4-dimethyl-l-phenethylpyridinium bromide2,6-dimethyl-l-phenethylpyridinium bromide5-ethyl-2-1nethyl-l-phenethylpyridinium bromideot-picoline-fi-naphthoylmethylbromide1-;5'-phenylcarbamoyloxyethyl-Z-picolinium bromideanhydro-l-(4-sulfobutyl)-2-picolinium hydroxide2-ethyll-phenethylpyridinium bromide 1-[3-(N-pyridiniumbromide)propyl]-2-picolinium-ptoluenesulfonate1-methyl-2-picolinium-p-toluenesulfonatel-phenethyl-2,4,G-trimethylpyridiniurn bromide1-phenethyl-4-n-propylpyridinium bromide 4--hydroxypropyl-l-phenethylpyridinium bromide l-n-heptyl-Z-picoliniumbromide 2-isopropyl-l-phenethylpyridinium bromide tetraphenylammoniumbromide tetraethylammonium bromide N-eahylpyridinium bromideN,N-diethylpiperidinium bromide ethylene-bis-pyridinium bromide1-phenethyl-3-picolinium bromide cetyltrimethylammonium bromidepolyethylene oxide bis-pyridinium perchlorate3-methyl-2-ethylisoquinolium bromide B-methylisoquinoliniummethyl-p-toluenesulfonate 1-ethyl-2-methyl-3-phenethylbenzimidazoliumbromide 5,6-dichloro-1-ethyl-2-methyl-3-(3-sulfobutyl)-benzimidazoliumbetaine lauryldimethylsulfonium-p-toluenesulfonatenonyldimethylsulfonium-p-toluenesulfonateoctadimethylsulfoniurn-p-toluenesulfonate butyldimethylsulfonium bromidetriethylsulfonium bromide dodecyldimethylsulfonium-p-toluenesulfonatedecyldimethylsulfonium-p-toluenesulfonate phenyldimethylsulfoniumbromide phenethyldimethylsulfonium bromide tetraethylphosphonium bromideethylene-bis-oxymethyltriethylphosphonium bromide tetraphenylphosphoniumbromide phenethyltrimethylphosphonium bromide The onium compounds can beused in a wide range of concentrations in dye developer diffusiontransfer systems, optimum amounts varying with the particular oniumcompound. Typical useful amounts of the onium compounds in the alkalineprocessing compositions range from about 2% to 15% by weight of oniumcompound based on the weight of the processing composition.

When water-soluble silver halide solvents are employed in processingcompositions used in dye developer transfer systems, particularly inconjunction with onium compounds and colorless hydroquinone derivativesas described above, further improvement in color quality results.Preferred silver halide solvents are thiosulfates such as sodium,potassium and ammonium thiosulfate. Other suitable silver halidesolvents include thiocyanates, N,N- diethyl-l,3-propanediamine,triethanol amine, aminoethanol, ammonium hydroxide, and the like. Suchsilver halide solvents are preferably incorporated in the alkalineprocessing composition in amounts of about .8 to 2% by weight, althoughthey can also be positioned in the reception layer for the dye images.Substantially no silver halide is transferred to the reception layers,and thus, the present process is to be distinguished from silver halidediffusion transfer processes.

The silver halide emulsions utilized in preparing photographic orlight-sensitive elements used in the present diffusion transfer systemscan be any of the conventional negativetype, developing-out emulsions.Typical suitable silver halides include silver chloride, silver bromide,silver bromoiodide, silver chloroiodide, silver chlorobromoiodide andthe like. Mixtures of more than one of such silver halides can also beutilized. In accordance with usual practice, such silver halideemulsions can contain spectral sensitizers, speed-increasing addenda,hardeners, coating aids, plasticizers, antifoggants and the likeconventional emulsion addenda.

In preparing such silver halide emulsions, as well as in preparing thevarious layers of photographic elements used in the present diffusiontransfer systems, including the layers containing the dye developers andcolorless hydroquinone derivatives, interlayers, topcoat layers and thelike, hydrophilic organic colloids composed primarily of gelatin areutilized as the vehicle or carrier. Minor amounts of other hydrophiliccolloids or carrier materials can be used With gelatin such as polyvinylalcohol and its water-soluble derivatives and copolymers, water-solublecopolymers such as polyacrylamide, immidized polyacrylamide, etc., andother water-soluble film-forming materials that form water-permeablecoats such as colloidal albumin, water-soluble cellulose derivatives,etc., can be utilized in preparing the photographic elements. However,such vehicles or carriers preferably consist essentially of gelatin.

The various layers utilized in preparing the diffusion transferphotographic elements used in the process of the invention can be coatedon a wide variety of photographic supports. Typical supports includecellulose nitrate film, cellulose acetate film, polyvinyl acetal film,polystyrene film, polyethylene terephthalate film, polyethylene film,polypropylene film, paper, polyethylene-coated paper, glass and thelike.

Similarly, a wide variety of receiving sheets can be utilized to receivethe transfer images from the photographic eleme nts. Typical receptionlayers for receiving sheets include such materials as linear polyamides,proteins such as gelatin, polyvinyl pyrrolidones, poly-4-vinyl pyridine,polyvinyl alcohol, polyvinyl salicylal, partially hydrolyzed polyvinylacetate, methyl cellulose, regenerated cellulose, or mixtures of such.These reception layers can be coated on a suitable support of the typedescribed above for the light-sensitive elements of the invention andincluding transparent as well as Opaque supports. Also, receiving sheetsthat release acidic material such as that derived from an acidic polymeror other acidic compound at a controlled rate as are described in U.S.Pat. No. 2,584,030 are particularly useful. Such acidic materials aretypically positioned in layers on the receiving sheet below the dyedeveloper reception layer, there suitably being a spacer layer betweenthe acid layer and the mordanting layer to control the release of acidicmaterial. Such acidic materials serve to neutralize residual portions ofthe alkaline activator on the receiving sheet. A Wide variety ofnondiffusible cationic or basic dyemordanting compounds can be used inliquid permeable reception layers including amines such as polymericamines, quaternary ammonium compounds, quaternary phosphonium compoundsand tertiary sulfonium com pounds. Such mordants are nondiffusible inthe alkaline processing composition and contain at least one hydrophobicballast group. The receiving sheets can also contain developmentarrestors such as mercaptoazoles and iodides.

Light-sensitive elements containing integral reception layers for dyedeveloper images can also be utilized. Such integral reception layerscan be coated beneath the emulsion and dye developer layers near thesupport. A stripping layer coated over the integral reception layer canbe used to facilitate the removal of the overcoated layers after thediffusion of the dye developer images to the reception layer.

The processing compositions or activators used to initiate developmentof the exposed light-sensitive ele-' ments in accordance with theinvention are strongly alkaline. Such processing compositions generallyhave a pH of at least 12 or contain at least .01 N hydroxyl ion. Alkalimetal hydroxides, such as sodium hydroxide, and sodium carbonate, areadvantageously used in the composition for imparting such highalkalinity. However, volatile amines such as diethyl amine can also beused, such amines having the advantage of being volatilized from theprints to leave no residue of alkali.

Camera apparatus of the type useful for exposing and processing imagediffusion transfer systems have been described, for example, in U.S.Pat. No. 2,435,717. Such cameras permit successive exposure ofindividual frames of the photosensitive element as well as processing ofexposed frames. With such cameras, the exposed portion of thephotosensitive element is brought in superposed relation with a portionof an integral print receiving element with a container for alkalineprocessing material therebetween, the alkaline processing materialdesirably containing a viscosity increasing agent such as hydroxyethylcellulose or carboxymethyl cellulose. The film assembly is then drawnbetween a pair of pressure rollers which rupture the processingcomposition container and spread the alkaline processing compositionbetween and in contact with the photosensitive element and thecorresponding register area of the print receiving element. Thephotosensitive element and print receiving element during the spreadingof the container contents become formed into a combination wherein thephotosensitive element and print receiving element are so superposedwith respect to each other that the spread alkaline processingcomposition has access to both of the elements. This superposedrelationship between the photosensitive and print receiving elements ismaintained until the elements are stripped apart following the depositon the print receiving element of the dye developer forming the finalpositive color image.

The processing of photographic elements in the present diffusiontransfer process can also be effected in accordance with the inventionoutside of camera apparatus. A typical suitable-processing means isillustrated by FIG. 2 of the drawing described hereinbelo-w.

In the accompanying drawing are shown in enlarged cross-sectional viewrepresentative elements and processing means employed in the invention.

In FIG. lot the drawing is shown in flow-sheet form a typical processembodying our invention according to which in Stage 1 thelight-sensitive element comprises support 10, layers 11, 12 and 13containing subtractively colored cyan, magenta and yellow dyedevelopers, respectively, light-sensitive silver halide emulsion layers14, 15 and 16 sensitive to red, green and blue light respectively,feature gelatin interlayers 17 and 18 described in detail hereinseparating the green-sensitive emulsion and its contiguous subtractivelycolored magenta dye developer layer from the other layers and overcoatlayer 19, the colorless hydroquinone derivatives described abovetypically being positioned in layer 19. A receiving sheet comprisingsupport 20 having coated thereon reception layer 21 is superposed toreceive dye images transferring by diffusion from the light-sensitiveelement. Positioned between the light-sensitive element and thereceiving sheet is a rupturable container or pod containing alkalineproc essing composition 22. Upon rupture of the container holdingalkaline processing composition 22, such as by passing the assemblybetween rollers in a camera, the contents of the container aresubstantially uniformly spread across a predetermined area of thesensitive element. The viscous processing composition penetrates throughlayers 19 to 11, latent images develop in lightsensitive layers 14, 15and 16 and dye developers in con tiguous layers 11, 12 and 13respectively rendered nondiffusing in areas corersponding to latentimage or negative areas such as 23, 24 and 25, and the dye developers inthe remaining or positive image areas diffuse image- WlS6 in register tomordant or reception layer 21 of the receiving sheet. State 2 of FIG. 1illustrates receiving sheet support 20 with reception layer 21containing transferred dye developers to form subtractively coloredpositive images, namely, yellow image 26, magenta image 27 and cyanimage 28.

FIG. 2 of the drawing illustrates a typical light-impervious enclosureuseful for processing exposed rolls of film containing silver halideemulsion layers and dye developers of the type described above. Inutilizing the processing means of FIG. 2, film 30, wound emulsion sideinwards, is passed between rollers 31 and 32. Roller 32 is immersed inalkaline processing composition 33. Roller 32 transfers portions ofalkaline processing composition 33 to the emulsion lavers on film 30.Thereafter film 30 is conveyed between rollers 35 and 36 Where theemulsion layer side of film 30 is brought into contact with mordantedreceiving sheet 37 to form sandwich 38. In sandwich 38, the exposedsilver halide in each emulsion layer develops, contiguous dye developersbecome immobilized and unreacted dye developers transfer to mordantedreceiving sheet 37. Thereafter sandwich 38 is conveyed over roller 39and stripped apart to provide positive dye de veloper images onmordanted receiving sheet 37 at 40.

The following examples will serve to further illustrate the presentinvention.

EXAMPLE I A photographic element having the structure substantially asshown in FIG. 1 of the drawing (layers 10 to 19) was prepared by coatingsuccessively the following layers on a subbed cellulose acetate filmsupport;

(1) Cyan dye developer layer (e.g., layer No. 11 of FIG. 1).A coating ofthe cyan dye developer, 5,8-dihydroxy-l ,4 -bis(Ii-hydroquinonyl-d-methyl ethylamine] anthraquinone, dissolved inN-n-butylacetanilide, dispersed in gelatin and coated at a coverage of210 mg. per square foot of the cyan dye developer and 250 mg. per squarefoot of gelatin. The dye developer dispersion was prepared by adding toan aqueous gelatin solution 1 part by weight of the cyan dye developerdissolved in 1.5 parts by weight of N-n-butylacetanilide and 2 parts byweight of 4-methylcyclohexanone in the presence of a sodiumdiisopropylnaphthalene sulfonate dispersing agent. The mixture waspassed through a colloid mill several times, chill set, shredded, driedto volatilize the 4-methylcyclohexanone, melted and coated.

(2) Red-sensitive emulsion layer (e.g., layer No. 14 of FIG. l).Acoating of a developing-out negative gelatino-silver bromoiodide (6%iodide) emulsion sensitized to red light was coated at a coverage of 180mg. per square foot of silver and 200 mg. per square foot of gelatin.

(3) Interlayer (e.g., layer No. 17 of FIG. l).A coating of gelatin atcoverages described below.

(4) Megenta dyed developer layer (e.g., layer No. 12 of FIG. l).Acoating of the magenta dye developer, 2 [p(2',5'-dihydroxyphenethyl)-phenylazo]-4-n-propoxy-l-naphthol, dissolvedin N-n-butylacetanilide dispersed in gelatin and coated at a coverage of60 mg. per square foot of the dye developer, 75 mg. per square foot ofgelatin and 60 mg. per square foot of N-n-butylacetanilide. Thedispersion of the dye developer was prepared by dispersing in an aqueousgelatin solution 1 part by weight of the dye developer in 2 parts byweight of cyclohexanone and 1 part by weight of N-n-butylacetanilide inthe presence of the dispersing agent, sodium diisopropylnaphthalenesulfonate. The resulting mixture was passed through a colloid millseveral times, chill set, washed to remove the cyclohexanone, melted andthereafter coated.

(5) Green-sensitive emulsion layer (e.g., layer No. of FIG. l).A coatingof a developing-out negative gelatino-silver bromoiodide (6% iodide)emulsion sensitized to green light was coated at a coverage of 75 mg.per square foot of silver and 70 mg. per square foot of gelatin.

(6) Interlayer (e.g., layer No. 18 of FIG. l).A coating of gelatin atcoverages described below.

(7) Yellow dye developer layer (e.g., layer No. 13 of FIG. l).A coatingof the yellow dye developer, 1-

phenyl3-N-n-hexylcarboxamido-4-[p-(2',5-dihydroxyphenethyl)phenylazo]-5-pyrazolone,dissolved in ditetrahydrofurfuryl adipate and dispersed in gelatin wascoated at a coverage of 7-5 mg. per square foot of the dye developer,mg. per square foot of gelatin and 30 mg. per square foot ofditetrahydrofurfuryl adipate. The dispersion was prepared by dispersingin an aqueous gelatin composition, 1 part by weight of the dye developerdissolved in .5 part by Weight of ditetrahydrofurfuryl adipate and 2parts by weight of ethylene glycol monobenzyl ether in the presence of asodium diisopropylnaphthalene sulfonate dispersing agent. The mixturewas passed through a colloid mill several times, the resultingdispersion chill set, washed to remove the ethylene glycol monobenzylether, melted and coated.

(8) Blue-sensitive emulsion layer (e.g., layer No. 16 of FIG. l).Acoating of a developing-out negative gelatino-silver bromoiodide (6%iodide) emulsion that is inherently sensitive to blue light was coatedat a coverage of mg. per square foot of silver and 40 mg. per squarefoot of gelatin.

(9) Overcoat layer (e.g., layer No. 19 of FIG. 1). A gelatin coatingcontaining dispersed therein the colorless auxiliary developer,4'-methylphenylhydroquinone (referred to hereafter as MM-IQ), dissolvedin di-nbutylphthalate at a coverage of 120 mg. of gelatin per squarefoot and 40 mg. of MPHQ per square foot. The dispersion was prepared asfollows.

Hydroquinone derivative dispersion D-l Part AHeat at C. to dissolve,then cool to 40 C.:

4-methylphenylhydroquinonel36 g. Methyl alcoholl36 ml.Di-n-butylphthalate-272 ml.

Part B--Heat to 40 C.:

10% gelatin solution-1360 g. Waterl360 ml. Mucochloric acid (2.7%aqueous solution)136 ml.

Part A was slowly added to Part B with the aid of mechanical agitation.The solution obtained was then passed through a colloid mill five times.The colloid mill 12 was then rinsed and the dispersion was adjusted to aweight of 3,775 g., chill set and stored in a refrigerator. The coatingcomposition for the overcoat layer (e.g., layer 19 of FIG. 1) wasprepared as follows.

Part IHeat to 40 C.:

Dispersion D1-3,775 g. Water-2,225 ml.

In order to demonstrate the effect of varying amounts of gelatin in theinterlayers (e.g., layers 17 and 18 of FIG. 1), several films having thebasic structure described above were prepared in which the gelatincontent of layer 17 was 7-5, 150 and 200 mg. per square foot and forlayer 18 was 75, 150, and 300 mg. per square foot. These films aredesignated as Films A, B and C respectively in the tables below. Similarfilms containing no MPHQ in layer 19 were prepared and are designatedFilms D, E and F in the tables below. The thicknesses in mils of thelayers of Films A, B and C are shown in Table I.

It can be seen from these measurements that in Films B and C, theinterlayers, 17 and 18, are at least or as thick as the yellow dyedeveloper layer, 13. When cross-sections of these films are viewed at amagnification of the order of 1500 the Film A layers 12 and 15 appear toalmost touch layers 14 and 13 respectively, whereas in Films B and C,layers 12 and 15 are distinctly separated from layers 14 and 13 asillustrated in FIG. 1, Stage 1 of the drawing. The films were eachexposed under a step tablet to red, green and blue light and each wettedwith either Activator I or Activator II in contact with either ReceivingSheet A or B, the activators and receiving sheets being described below.The films and the receiving sheets were left in contact for 3 minutes at70 F. and then stripped apart to give multicolor images on the receivingsheets. As a result the silver halide developed in exposed areas 23, 24and 25 of each sample, and the dye developers in the contiguous areas oflayers 13, 12 and 11 thereunder became immobilized as a function of thedevelopment and the unreacted dye developers diffused imagewise and inregister to the receiving sheet to yield a colored positive imagecomposed of images 26, 27 and 28 as shown in Stage 2 of the drawings. Inthis process, the use of the interlayers of suitable thickness incooperation with the colorless hydroquinone auxiliary developer,4-methylphenylhydroquinone, the dye developers in each of layers 11, 12and 13 became immobilized at the required rate, extent and in the properlayers, particularly when the processing was carried out in the presenceof an onium compound. Density measurements were then made upon theresulting neutral scale and red scale of each print through red, greenand blue filters to obtain the density values shown in Table II below.The activators or alkaline processing compositions referred to had thefollowing composition:

Activator I An aqueous solution containing 3.5% high viscosityhydroxyethyl cellulose, 4.5% sodium hydroxide, 2% benzotriazole, 2%1-benzyl-2-picolinium bromide and 1% sodium thiosulfate.

Activator II An aqueous solution containing 3.5% high viscosityhydroxyethyl cellulose, 4.5% sodium hydroxide, 2% benzotriazole and 1%sodium thiosulfate.

Higli viscosity hydroxyethyl cellulose sold by Hercules Powder Co. asNatrosol 250 Type H having a viscosity of about 10,00015,000 cps. at 25C. as 2% aqueous solution.

The receiving sheets referred to had the following composition: i 1

Receiving sheet A Receiving sheet B A paper support carrying a gelatin300 mg. per square foot) layer containing a mixture of poly-4-vinylpyridine (300 mg. per square foot), l-phenyl-S-mercapto tetrazole mg.per square foot) and l-phenethyl-Z-picolinium bromide (100 mg. persquare foot).

14 emulsion layer and an underlying contiguous gelatin layer containinga dye developer diifusible in alkaline liquid and substantiallycomplementary in color to the color of light recorded in the contiguousgelatino-silver halide emulsion layer, a substantially colorless andsubstantially water-insoluble hydroquinone soluble and diffusible inalkaline solution through the layers of said element positioned in atleast one of the layers on the emulsion side of said element,hydrophilic organic colloid interlayers comprising gelatin separatingthe said imageforming units, said interlayers being capable of delayingdiffusion of dye developer from one dye image-forming unit to anotherdye image-forming unit for a time sutficient to effect substantialdevelopment of the re- TABLE II Ratio Layer 18 Layer 17 oi cyan NeutralScale Red scale den- Thick- Thickmi... sity, 1st step Magenta Mg./gel/ness, Mg./gel/ ness,

Test No Film Activator Receiver it? mils it! mils R G B R G B densitiesI A. 150 03 150 04 35 27 49 67 1. 34 1. 81 1:2. 0 I A 200 04 300 07 2840 56 1. 43 1. 85 1:2. 56 I A 75 .01 75 .02 .26 .24 .26 .60 1.03 1. 5911.73 I A 150 03 150 04 22 v 22 24 39 1. 12 1. 74 1:2. 89

I A 200 .04 300 .07 .20" .21 .25 .23 1.26 1.72 1:5.5 II A 75 01 75 02 2287 55 75 1. 55 1. 85 1:2. 08 II A 150 03 150 04 20 54 94 70 1. 61 1. 931:2. 32 II A 200 04 300 07 14 51 1. 08 64 1. 70 1. 91 1:2. 68 II A 75.01 75 .02 .18. .30 .41 .40 1.17 1. 56 1:294 11 A 150 03 150 04 15 4334 1. 29 1. 73 1:3. 82 II A 200 04 300 07 14 27 42 30 1. 48 1. 88 1:4.95 II B 75 01 75 02 27 39 60 79 1. 41 1. 79 1: 1. 79 II B 150 03 150 0427 66 71 1. 1. 87 1:2. 04 II B 200 04 300 07 24 41 76 61 1. 60 1. 921:2. 64 II B 75 01 75 02 20 22 28 49 1. 06 1. 57 1:2. 17 II B 150 03 15004 16 19 28 29 1. 15 1. 71 1:4. 00 II B 200 04 300 07 .20 23 31 26 1. 361.86 1: 5. 25

The data in Table 11 illustrates the improved multicolor transfer imagesthat result from the novel features of the present dye developerdiffusion transfer system. The data particularly illustrates theretarding of the diffusion of the magenta dye developer tothered-sensitive emulsion layer, and the retarding of the diffusion ofthe cyan dye developer upward, to produce red colors having lesscontamination with other colors and more saturation in accordance withthe invention. Such improvements are indicated by substantial decreasesin the ratio of cyan to magenta dye densities in the red scale, asmeasured by red (R) light and green (G) light. Tests 10, 11 and 12illustrate the cooperation of the feature gelatin interlayers and theauxiliary hydroquinone developer to produce the improvements of theinvention. Tests 4, 5 and 6, as well as Tests 16, 17 and 18, illustratethe further cooperating eifect of an onium salt in the system with thefeature gelatin interlayers and auxiliary hydroquinone developer.Similar improvements are not obtained with other developing agents suchas p-methylaminophenol, l-phenyl- 3-pyrazolidone, 4-phenylcatechol,4-amino-5-methy1 resorcinol, 2-amino-5-methyl resorcinol, pyrogallolmonocarbonate and 1 phenyl-4,4-dimethyl 3 pyrazolidone when substitutedfor the present auxiliary hydroquinone developing agents.

The invention has been described in considerable detail with particularreference to preferred embodiments thereof, but it will be understoodthat variations and modifications can be effected within-the spirit andscope of the invention as described hereinabove and as defined in theappended claims.

I claim:

1. A photographic product composed of a photosensitive elementcomprising a support having coated thereon three superposed dyeimage-forming units in layers capable of recording red, green and bluelight, the dye imageforming unit recording blue light being furthestfrom the support and the dye image-forming unit recording red lightbeing most proximate to the support, each of said image-forming unitscomprising a gelatino-silver halide spective silver halide emulsions bydye developer from the said layer coated contiguous to each suchemulsions when said element is processed in the presence of an alkalineprocessing composition, a dye developer reception layer, and arupturable container containing an aqueous alkaline processingcomposition, said photosensitive element and said dye developerreception layer being capable of being superposed on each other, saidcontainer being so positioned as to be capable, upon being ruptured, ofreleasing said processing composition for application to said superposedphotosensitive element and reception layer, said alkaline processingcomposition containing a heterocyclic quaternary ammonium compoundcapable of forming a diffusible methylene base in said alkalinecomposition and having the formula wherein (a) n is an integer of O to1,

(b) Zrepresents the nonmetallicatoms necessary to complete aheterocyclic nucleus,

(c) X is an anion,

(d) 'R is selected from the group consisting of an alkyl radical, anaryl radical and an aralkyl radical, and

(e) R is selected from the group consisting of a hydrogen atom and alower alkyl radical.

2. A photographic product as described in claim 1 wherein thesubstantially colorless and substantially water-insoluble hydroquinoneis selected from the group consisting of:

phenylhydroquinone 2'-hydroxyphenylhydroquinone phenoxyhydroquinone4'-methylphenylhydroquinone 1,4-dihydroxynaphthalene2-(4-aminophenethy1)-5-bromohydroquinone2-(4-aminophenethyl)-5-methylhydroquinone 154'-aminophenethylhydroquinone 2,5 -dimethoxyhydroquinone2,5-dibutoxyhydroquinone m-xylohydroquinone bromohydroquinone 3,6-dichlorohydroquinone 2-dimethylaminoethyltoluhydroquinoneZ-cyclohexylhydro quinone sec.-butylhydroquinone2,5-dichlorohydroquinone 2,5-diisopropylhydroquinone2,5-diiodohydroquinone 3 -chlorotoluhydroquinone tetrachlorohydroquinone2,5-diphenylhydroquinone 2,S-diresorcylhydroquinone 2,5-dioctylhydroquinone, and dodecylhydroquinone.

3. A photographic product as described in claim 1 wherein thesubstantially colorless and substantially wa ter-insoluble hydroquinoneis 4' methylphenylhydroquinone.

4. A photographic product as described in claim 1 wherein the silverhalide is silver bromoiodide.

5. The process for preparing multicolor photographic diffusion transferdye developer images which comprises treating an exposed photographicproduct as described in claim 1 with said alkaline processingcomposition by rupturing said container, developing latent images in theregions of exposure of the silver halide emulsion layers and therebyimmobilizing dye developers in said regions of exposure, dye developersin undeveloped regions diffusing imagewise in register to said dyedeveloper reception layer.

6. The process for preparing multicolor photographic diffusion transferdye developer images as described in claim 5 wherein the aqueousalkaline processing composition contains about 2% to 15% ofl-benzyl-Z-picolinium bromide based on the weight of said aqueousalkaline liquid.

7. The process as described in claim 5 wherein the alkaline processingcomposition contains a silver halide solvent.

8. The process as described in claim 5 wherein the alkaline processingcomposition contains hydroxyethyl cellulose as a thickening agent.

9. The process as described in claim 5 wherein the reception layer forthe dye developer images contains a silver halide development arrestor.

References Cited UNITED STATES PATENTS 2,983,606 5/1961 Rogers 96--33,019,108 l/l962 Dershowitz 9666.3 3,129,097 4/1964 Emiel van Hoof eta1. 9628 NORMAN G. TORCHIN, Primary Examiner A. T. SURO PICO, AssistantExaminer U.S. Cl. X.R.

